Pulldown device



Jan 25, 1949- v. E. RICHARDSON l 2,459,840

YPULL DOWN DEVICE Filed Feb. 13, 1945 Patented Jan. i?5, 1949 PULLDOWN DEVICE Vernon E. Richardson, Albuquerque, N. Mex., as-

signor to Continental Oil Company, Ponca City,` Okla., a corporation of Delaware Application February 13, 1943, Serial No. 475,717

8 Claims. (Cl. 2li-263.5.)

y My invention relates to improvements in pull- L down or force feed devices for rotary well drilling equipment.

Rotary well drilling rigs of the type employed in the instant invention have a vertical kelly or shaft attached to the string of drill pipe in the bore hole. The kelly is continuously driven to rotate the drill pipe and as the Well bore deepens it moves downwardly to feed the drill pipe into the hole. When the kelly reaches the lower limit f of its travel it is disengaged from the string of drill pipe and raised. A new section of drill pipe is then attached to the string and the kelly connected to the new section.

drilling hard strata the string of drill pipe does not have suiiicient weight to give a proper cutting action. Under these circumstances it is necessary to apply downward pressure on the drill pipe. The mechanism for applying the downward pressure is usually referred to as a pull-down or force feed device.

In the past, several types of pull-downs have been used. For example, downward pressure has been brought to bear on the drillpipe by attaching the cable of a power winch to the kelly. This practice is generally unsatisfactory however because it frequently bends or warps the expensive kelly. Furthermore, it is a dangerous procedure since the cable sometimes breaks and Whips about, injuring workmen and damaging property.

Downward pressure has also been brought to bear on the drill pipe by chucking a hydraulic unit to the kelly. However, since conventional hydraulic units have a limited vertical stroke of from one to four feet, the chuck must be readjusted on the kelly many times during each stroke of the kelly. The chucks are manuallyV adjustable, hence considerable time is consumed in making the adjustments. Furthermore, the drilling operation is prolonged since the rotary driven mechanism must be stopped each time the chuck is readjusted.

I propose to replace the chuck connecting the hydraulic to the kellyvwith a pull-down device associated with the kelly in sucha way that it automatically releases the kelly on the upstroke of the hydraulic and automatically attaches to the kelly on the downstroke of the hydraulic. The automatic pull-down eliminates the tedious, arduous and time consuming task of rechucking and makes it unnecessary to stop the drilling mechanism after each stroke of the hydraulic.

' In the drawing forming a part'of this specifi- 2 cation and wherein like numerals are employed to designate like parts throughout the same,

Figyl is a top plan View of an automatic pull-l downdevice employing my invention, parts being broken'away for clearness of illustration,

Fig. 2 is a side elevation of the automatic pulldown, parts being broken away and partsbeing shown in section to more clearly illustrate the assembly and the relation of the respective parts,

Fig. 3 is a fragmentary vertical section through the bottom `of the housing of the pull-down device illustrating one of the cams of the operating ring,

Fig. 4 Yisa fragmentary'vertical section taken 15 through another point at the bottom of the house During the initial drilling operations or when ing illustrating relation ofV :the operating ring, lower ring plate;and connecting bolt.

In the drawing wherein for the purpose of illustration is shown a preferred embodiment of the invention, the numeral I0 designates the fragmentary lower end of the quill assembly through which a kelly Il extends and to which the pulldown device comprising my invention is attached, the kelly illustrated being of hexagonal 'cross section. The quill and kelly are secured for mu tual rotation and the quill is slidable on the kelly. Thejquill is adapted to be rotatably driven and in turn rotates the kelly and the string of drill pipe (not shown) secured tothe lower end of the kelly. Simultaneously the quill is reciprocated on the kelly by a hydraulic unit (not shown) in a manner wellknown to those skilled in the art of drill; ing earth formations. When the quill is raised the pull-down automatically releases the y kelly and when the quill is lowered the pull-'down automatically attaches to the kelly, applying downward pressure onthe drill pipe.

The pull-down is mounted in a housing l2 hav-4 ing cylindrical walls I2a, a bottom I2b and a removable cover l2c threaded into the open top of the cylindrical wall and secured in place by cap screws 12d. The cover I2C is fastened to the lowerV end of the quill by bolts I2 so that the housing rotates andreciprocates with the quill.

On the downstroke of the hydraulic unit, the quill is coupled to the kelly by jaws l3-I3a and I3b slidably mounted in ways i4 arranged about an axial passageway I la. through which the kelly extends. The ways I4 are formed between c ir- Y cumferentially spaced radial pairs of guide plates or wings l5-l5a to engage a respective side of the hexagonal kelly. Each jaw carries artransverse pin I8 and la'that projects from the ref spective sidesthereof. Rollers I1 and l'laon the projecting ends of the pins ride-freely in slots'l and I 8a in the guide plates I5-I5a. The slots I8-I8a, are inclined toward the axis of the passageway and cooperate with the jaws to provi-de guiding means so that upward movement of the jaws I3, I3a and I3b engages them with the kelly and downward movement of the jaws releases them from the kelly. Springs I9 and I9a attached to the ends of pins I6 and I6a respectively, normally urge the jaws upwardly and against the kelly.

Pivoted on a pin 20 behind each jaw I3, I 3a and I3b and between their guide plates I5, 15a are gear segments 2l which mesh with a series of transverse gear teeth I4' on 4the upwardly inclined outer faces of the jaws. The gear segments `2I are freely movable about their vpivots on fixed axes so that they swing upwardly and downwardly with the jaws when the jaws are engaged with and released from the kelly when quill I rises and upwardly to engage the jaws with .the kelly when the quill is lowered. The springs I9 and I 9a provide the necessary friction to assure a binding engagement between the jaws and the kelly as soon as the Yquill begins its downstroke.

Occasionally, as when spudding or changing drill pipe, it is necessary to hold the jaws released from the kelly for a considerable length of time. For this purpose a movable release ring assembly is provided, The assembly comprises an upper ring plate 22 and a lower ring plate 23 iixedly connected in vertically spaced relation by stems or bolts 24. As best shown vin Fig. 2, the upper ring plate 22 is disposed above the jaws and the lower ring plate 23 is disposed Vbelow the bottom of the housing. 'Connecting bolts 2.4 extend through openings 24 in the bottom I 2b of the housing I2 and are supported by bosses 25. The upper ring plate 22 is normally held above the jaws by springs 26. When the release ring assembly is moved downward to press the tapered face 2 Ia of the upper ring plate 22 against the tapered top surface I4b of the jaws, the jaws are spread and held away from the kelly. The ring plate assembly is moved downwardly by manual operation of an actuator plate 2 'I interposed between the lower ring plate and the bottom of the housing. Actuator plate 21 is rotated by handles 21a which project radially beyond the housing I2. slots^2.1' which accommodate the bolts 24 and permit it to have a limited rotational movement. Depending from actuator plate 2,1 and .extending through slots 23 in the ring plate 23 is a plurality of cams 28 having inclined edges 28'. When actuator plate 27 is rotated the inclined edges 2.8' of cams 28 ride upon the inclined cam surfaces 23" at one end of each slot 2.3 lowering the ring plates 22 and 23. When the actuator plate 2l has reached the limit of its travel to lower the release ring assembly, cams 28 have passed beyond slots 23' and rest upon the inner surface of ring 23 to hold the release ring assembly in the lowered position. In this position of the assembly the upper ring 22 holds jaws I3, I3a and 53h spread apart and released from kelly I I.

It may vthus be seen that I have accomplished the objects of my invention. I have provided .an automatic pull-down device that, when substituted for the chuck coupling the hydraulic to the kelly, will automatically release the kelly on the upstroke of the hydraulic and automatically engage the kelly on the downstroke of the hydraulic. Since my pulldownis `attached to kthe quill, it

' Ihe actuator plate v2'I .has arcuate 4 at all times rotates synchronously with the kelly making it unnecessary to stop the rotary driven mechanism during readjustment of the pulldown. My pull-down applies downward pressure on the drill pipe without danger of bending or warping the kelly and eliminates the tedious, arduous and time consumingV task of manually rechuckingaf-ter each limited movement of the hydraulic. It is obvious "that with the structure illustrated and described the jaws are free to move with movement of the kelly relative to the Y axis of :the kelly passageway and that by reason of the gear segments and their tooth connections with the jaws, the jaws are maintained in gripping contactwith the kelly.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example o1 the same and that various changes inthe size, shape and arrangement vofV parts ,may be resorted to ,without departing from thespirit of my invention or .the scope of the appended claims. I

Having thus described my invention,.1 claim:

1. A pull-down device including a housing hav.- ing an axial .passageway for a member to be gripped, a Yplurality of jaws arranged about said passageway to engage said member to be gripped and havingzouter portions inclined relative tothe axis of the passageway, correspondingly inclined guide means between the housing and the respective jaws for individual movement of said jaws inanup and down direction while moving toward and away from said axis of the passageway, springs between the jaws and the housing for moving the jaws in a direction to grip said member, a jaw backing member for each jaw and having an arcuate portion related to the inclined portion of the jaw backed thereby, said related inclined and arcuate portions Yhaving interengaging means for .maintaining interconnection of said jaws and their backing members, means pivotally supportingthe jaw backing members in the housing forrocking movement on fixed axes for maintaining said jaws in `gripping contact With said member, and manual means for moving the jaws againstactionof said springs to release said jaws.

2. A pull-down device including a housing having an axial passageway for a member to .be gripped,a plurality of jaws arranged about said passageway to engage said member to be gripped and having outer portions inclined relative to the axis of the passageway, correspondingly inclined guide means between the housing and `the respective jaws for individual .movement of vsaid jaws in an up and down direction while moving toward and away from said axis of the passageway, springs between the jaws and the housing for moving the jaws in a .direction to grip said member, a jaw backing member for each jaw and having an yarcuate portion related to the inclined portion of .the jaw backed thereby, said related inclined and arcuate portions having means pivotally supporting the jaw backing members in the housing for rocking movement on xed axes for maintaining, Said jaws in gripping Contact with said member, shift means engageable with each jaw for movement of the jaws in opposition to action of said springs', an actuator Vfor operating said shift means, and means extending through the housing intermediate the jaws for connecting saidshift means with the actuator.

3. A pulladown device including a housing having .an axial, passageway for a member to-be grippedja plurality of jaws arranged about said passageway to engage said member to be gripped and having outer face portions inclined toward the axis of said passageway, correspondingly inclined guides in the housing, means on the jaws freely engaged with said guide means for individual movement of the jaws in an up and down direction while moving toward and away from the axis of said passageway, springs between the jaws and the housing for moving the jaws in a direction to grip said member, the inclined outer face portions of the jaws having a series of transverse teeth, gear segments having a plurality of tooth contacts with the teeth of the jaws, means pivotally supporting the gear segments in the housing for rocking movement on xed axes for backing and maintaining said jaws in gripping contact with said member when the jaws are under action of the springs, and manual means for moving the jaws against action of the springs to release said jaws.

4. A pull-down device including a housing having an axial passageway for a member to be gripped, a plurality of jaws arranged about said passageway to engage said member to be gripped and having outer face portions inclined toward the axis of said passageway, correspondingly inclined guides in the housing, means on the jaws freely engaged with said guide means for individual movement of the jaws in an up and down direction while moving toward and away from the axis of said passageway, springs between the jaws and the housing for moving the jaws in a direction to grip said member, the inclined outer face portions of the jaws having a series of transverse teeth, gear segments having a plurality of tooth contacts with the teeth of the jaws, means pivotally supporting the gear segments in the housing for rocking movement on fixed axes for backing and maintaining said jaws in gripping contact with said member when the jaws are under action of the springs, shift means engageable with the end of each jaw for movement of the jaws in opposition to said springs, an actuator for operating said shift means, and means extending through the housing intermediate the jaws for connecting said shift means with the actuator.

5. A pull-down device including a housing having an axial passageway for a member to be gripped, a plurality of jaws arranged about said passageway to engage said member to be gripped and having cuter face portions inclined toward the axis of said passageway, correspondingly inclined guides in the housing, means on the jaws freely engaged with said guide means for individual movement of the jaws in an up and down direction while moving toward and away from the axis of said passageway, springs between the jaws and the housing for moving the jaws in a direction to grip said member, the inclined outer face portions of the jaws having a series of transverse teeth, gear segments having a plurality of tooth contacts with the teeth of the jaws, means pivotally supporting the gear segments in the housing for rocking movement on fixed axes for backing and maintaining said jaws in gripping contact with said member when the jaws are under action of the springs, a jaw engageable member encircling the passageway in registry with the jaws, stems extending through the housing intermediate the position of the jaws and connected with the jaw engageable member, a carrier ring encircling the passageway exteriorly of the housing for supporting said stems, and an actuator 6. connected with said carrier ring for releasing the' jaws against action of said springs.

6. A pull-down device including a housing having an axial passageway for a member to be gripped', pairs of spaced wings arranged about the passageway for forming ways therebetween, jaws in said ways and having `outer face portions inclined relatively to the axis of said passageway, correspondingly inclined guide grooves in said wings, pins carried by the jaws and having ends loosely engaged in said guide grooves for guiding the jaws in an up and down direction while moving toward and away from the axis of said passageway, springs between the jaws and the housing for moving the jaws in a direction to grip said members, transverse teeth on said outer face portions of the jaws, gear segments in said ways having teeth meshing with the teeth of the jaws, pins extending transversely of the wings for mounting the gear segments to rock about xed axes responsive to movement of the jaws to and from said axis of the passageway for maintaining gripping contact of the jaws under action of the springs, and manual means for moving the jaws against action of the springs to release gripping contact of the jaws.

7. A pull-down device including a housing having an axial passageway for a member to be gripped, pairs of spaced wings arranged about the passageway for forming ways therebetween, jaws in said ways and having outer face portions inclined relatively to the axis of said passageway, correspondingly inclined guide grooves in said wings, pins carried by the jaws and having ends loosely engaged in said guide grooves for guiding the jaws in an up and down direction while moving toward and away from the axis of said passageway, springs between the jaws and the housing for moving the jaws in a direction to grip said member, transverse teeth on said outer face portions of the jaws, gear segments having teeth meshing with the teeth of the jaws, pins extending transversely of the wings for mounting the gear segments to rock about fixed axes responsive to movement of the jaws to and from said axis of the passageway for maintaining gripping contact of the jaws under action of the springs, a jaw engageabie member encircling the passageway in registry with the jaws, stems extending through the housing intermediate the pairs of wings and connected with the jaw engageable member, a carrier ring encircling the passageway exteriorly of the housing for connecting said stems, and an actuator connected with said carrier ring for releasing the jaws against action of said springs.

8. A device of the character described including a housing having an axial passageway for a member to be gripped, a plurality of jaws arranged about said passageway to engage said member to begripped and having outer surfaces inclined relatively to the axis of the passageway, correspondingly inclined guide means between the housing and the respective jaws for individual movement of the jaws in opposite axial directions of said passageway while moving toward and away from said axis, springs between the jaws and the housing for moving the jaws in one direction to grip said member, a jaw backing member for each jaw and having a peripheral surface for engagement with the inclined surface of its respective jaw, and means mounting the backing members for rotary movement in the housing with said peripheral surfaces in engagement with the inclined surfaces of the jaws for maintaining the vjaws in gripping Contact with said gripped member when the housing is shifted in one longitudinal direction wth respect to the axis of said passageway.

VERNON E. RICHARDSON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 346,784 Stamford Aug. 3, 1886 Number 1,500,459 12575,'993 1,590,469 1,310, IUS 1,372,105 1,384,57 17 1,909, 601 2,048,072 2 ,163,361

Johansen Feb. 16, 1943 

